In a mobile communication system, for information collection of parameter settings (e.g. an antenna tilt angle, transmission power, and a hand over parameter) in accordance with an installation environment of a base station and the like, a running test (drive test) or the like, for example, using a dedicated measuring instrument is performed. In the running test, using a measuring vehicle mounted with measuring equipment (e.g. a measuring instrument (radio wave measuring device) and a PC (Personal Computer) provided with a position information acquisition function) (or a measurement worker carrying a measuring device), radio wave measurement information such as received power, necessary position information, and the like are collected, and in a base station, a designated management device, or the like, information necessary for quality management of a cell area and the like are acquired. This drive test is well known for its many man-hours and high operation cost. In 3GPP (3rd Generation Partnership Project), specification development of MDT (Minimization of Drive Test) that is a technique in which collection of a wireless environment and position information is automated using a wireless terminal carried by a user has been progressing (refer to NPL 1). In a “Logged MDT” that is one form of MDT, for example, a UE (User Equipment) of an “Idle Mode” measures a wireless environment (specifically, e.g. a received power and a received quality of a Reference Signal), also acquires position information of a spot where the measurement has been performed using a GNSS (Global Navigation Satellite System) function such as GPS (Global Positioning System) or the like mounted on the UE, and logs a measurement result and the position information (further, measurement time information and the like). The UE transmits, upon transition, for example, from the Idle Mode to a connection state, the held Log data to a base station as a Measurement Report.
Further, an SON (Self-configuring and self-Optimizing Network) function of a network based on measurement information of a terminal is standardized (NPL 2). In SON, a terminal of a subscriber collects information of received qualities of peripheral base stations and problems of a communication quality of the past, instead of a measuring instrument. A base station collects traffic loads, problems of a communication quality of the past, parameter setting information, and the like. A part of pieces of the collected measurement information is shared among the peripheral base stations directly or via a network monitoring system. On the basis of a statistical analysis result of these pieces of the measurement information, setting environments of the base stations and the presence or absence of a problem of communication quality are determined, and parameters for each base station are updated on a network side. In this manner, optimization of a wireless access network is automated, which makes man-hour reduction, cost reduction, and network operation efficiency possible.
PTL 1 describes a problem that upon measurement using a terminal, since quality information (a reception level and a change in bit error rate) is collected assuming that a terminal (mobile station) is connectable to a mobile communication network, it is difficult to sufficiently collect information necessary for designing an area managed by a base station. For this problem, PTL 1 discloses a configuration in which a terminal includes a communication status information generation unit that generates, when the mobile station is unable to connect to a mobile communication network, communication status information including at least a cause (connection difficulty cause) for not being able to connect to the mobile communication network so as to be able to grasp a time zone and a position in which the mobile station is unable to connect to the mobile communication network.
Further, PTL 2 discloses a control device that tabulates, for each wireless cell, communication qualities reported from a plurality of mobile terminals each including a function for measuring and reporting a communication quality of a wireless line and generates histogram information. Further, disclosed with this control device is a system including a management device that acquires the generated histogram information and determines normality of communication for the each wireless cell via statistical processing based on a plurality of quality indexes from the histogram information. Having reliability is a prerequisite for measurements at the terminals for network adjustments assumed in PTL 2.